The operator has initiated a cyclic-steam-stimulation (CSS) project in the Opal A diatomite of the Sisquoc formation on the Careaga lease in the Orcutt oil field in Santa Barbara County, California. The operator has received entitlement to proceed with an expansion consisting of 110 additional new wells. This paper discusses steam-injection step-rate tests (SRTs) for this asset.
The target zone contains high oil content ranging from 1,800 to 3,000 bbl/acre-ft in massive intervals with 200- to 700‑ft thickness at depths of 600 to 1,000 ft and with a permeability of 5 to 15 md. The pilot currently consists of 19 cyclic-steam-injection wells configured in a 4×5 matrix spaced approximately 120 ft apart, producing from an average depth of 925 ft.
A supervisory control and data-acquisition system is used to control and monitor various aspects of field operations, especially the steam-injection-process protocols. Relatively low steam-injection rates of 250 to 450 B/D cold-water equivalent are used with 70% constant-quality steam. Steam-injection pressures and rates have been monitored closely throughout the process since startup in October 2009.
Case Study: Steam-Injection Step-Rate Tests Run in the Orcutt Oil Field
01 June 2016